Being good clones, they are all comparable in terms of hardware specifications, and their differences are down to each brand willingness to develop new firmwares.

I live in Ireland and the ongoing DVB-T testing phase allows me to receive the Irish TV quite well in my rural area, so I decided to have a closer look at their combo unit and flagship, the F16 introduced with an unusual commercial verbiage pairing the decoder features with the fighter jet homonym...

In final my decision to take a chance with a Dr.HD F16 has been motived by the following factors:
- The price, 250€ on eBay, (~287€ if bought on the seller's own web site, go figure!)
- The existence of a forum allowing users to communicate directly with the developers.
- More product information (videos, FAQ) than for most other brands.
- The regular release of firmware updates with improvement (they seems to be the only ones to entirely develop their own software).
- The fact that users from other brands are acually flashing their (C-Tech) decoder with DrHD firmware for better performance and more features...- The IF connectors are short-circuit proof (which is what likely toasted my Technomate unit).- Ability to playback the recorded video (.ts files) with Media Player Classic HC (for those reluctant to use the advertised GOM player. This should also work with VLC but not for me for some reason)

Conclusion:
After about 2 months of use, I'm still pleased with this receiver.
I had the opportunity to verify that the forum is attended, altough it is advisable to keep an eye on the russian forum as well (Google Translate is your friend). This allowed me to spot a bug fix for the network function (at time of writing, I use F16_010p_20110331_Log).
The receiver is fast and fully functional but has unexploited potential which hopefully will be unleashed through firmware updates.

July 2012 update: Since the last firmware in December 2011, it has become obvious that development for F16 came to a halt. With the announced F22 still to show up, it looks like Dr.HD is struggling with financial difficulties. Nevertheless, F16 remains a complete and stable device but with room for improvement.